Ablock has a volume of 0.09 m3 and a density of 4,000 kg/m3. what's the force of gravity acting on the block in water? a. 882 n b. 3,038 n c. 2,646 n d. 3,528 n

The formula for net force is mass times the acceleration of an object. 
F = ma
Where: m = mass
             a = acceleration due to gravity (9.8 m/s^2)
             F = Force

If you are pertaining to gravitational force, the acceleration of gravity is what you will consider which is 9.8 m/s^2

Now, you are given only the volume and density. We know that Density is mass over volume:



Using this we can extract a formula for mass:



The volume of your block is 0.09 and your density is 4000

Now input that into our formula:



Now that we know that mass = 360kg, we can now solve for our force.
F = ma
F = (360kg)(9.8m/s^2)
F = 3,528 N

The answer is then D.